A wide variety of locking mechanisms are known for engaging the back of a foldable blade of a knife for securing the blade in an open position. In one known mechanism, a locking bar is pivotally mounted to an upper part of the frame of the knife, and the pivotal connection is at a location intermediate the ends of the locking bar. One end of the locking bar engages the upper surface of the blade when the blade is in the open position to hold it in that position. When the end of the locking bar remote from the end which engages the blade is depressed, the end which engages the blade is raised and releases the blade to allows it to pivot to a closed position.
This mechanism is awkward to use because the user's grip on the handle must be altered to be able to depress the end of the locking bar which is remote from the blade.